<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .wrap {
      width: 200px;
      border: 1px solid #333;
    }

    .wrap:after {
      content: '';
      display: block;
      clear: both;
    }

    .left {
      float: left;
      background: blue;
      height: 100px;
      width: 100px;
    }

    .right {
      float: left;
      background: red;
      height: 50px;
      width: 100px;
    }

    .center {
      width: 50px;
      height: 50px;
      background: pink;
    }
  </style>
</head>

<body>
  <div class='wrap'>
    <div class="left"></div>
    <div class="right"></div>
  </div>
  <div class="center"></div>
</body>

</html>